S CIENCE P ROCESS S KILLS What does it take to work like a scientist?

W ORDS TO KNOW Observation Qualitative observation Quantitative observation Inference

Variables… Independent Variable: what the scientist changes on purpose Dependent Variable: the variable that changes because of the change in the independent variable Constants/Controls: the things that must stay the same within the experiment

S CIENTIFIC S CENARIO  R EAD AND APPLY THE STEPS OF THE SCIENTIFIC METHOD Ms. Gould noticed that some of her dry erase markers don’t always last as long as others. She wondered what the best brand to buy was. Based on prior experience she predicted that it was EXPO but wanted to test it out. She bought EXPO, Target brand and sharpie. She used the same color for the same amount of time each day and after 1 week the Sharpie stopped working, after 1.5 weeks the EXPO ran out and after 2 weeks the Target brand marker was still working. After looking over the results Ms. Gould determined that Target brand markers were the best. When she was finished she made sure to tell her teacher friends about the results so that they could buy the best brand as well.

State 2 observations and 2 inferences that you can make based on the picture to the right.

P ROCESS S KILLS INCLUDE : Posing Questions Observing Inferring Predicting Developing a hypothesis Designing Experiments Collecting Data Interpreting Data Drawing Conclusions Communicating Information

O BSERVATION Using one or more of your senses (sight, hearing, smell, taste and touch) to gather information about the world. Making and recording observations is the most basic skill in science. When you make observations, you want them to be accurate and objective; An accurate observation is an exact report of what your senses tell you; An objective observation avoid opinions, or bias, based on specific points of view

I S IT ACCURATE AND OBJECTIVE ? Example 1: Sixteen students were present for roll call, and five other students arrived afterward. Example 2: Half the class was late. Example 3: The friendliest people were the first to arrive.

O BSERVATIONS CAN BE Q UALITATIVE OR Q UANTITATIVE Qualitative observations are descriptions that do not use numbers; For example: colors, smells, tastes, textures or sounds Quantitative observations do include numbers; Counting objects, or measuring something with a standard unit; Often made using tools

I S IT Q UALITATIVE OR Q UANTITATIVE ? Example 4: The classroom walls are yellow. Example 5: The classroom floor is shiny. Example 6: There are 21 students in the room. Example 7: The chalkboard is 1 meter high and 2 meters wide

I NFERRING Making an inference, or inferring, is explaining or interpreting an observation or statement; It is based on observations and prior knowledge; Inferences should reasonable (logical), one that makes sense, given what a person knows about the topic and be based on accurate evidence; An inference may be unreasonable if it concludes too much from the evidence and should be avoided;

I S IT REASONABLE ? Suppose you are on safari in Africa. In a region bordering some small farms, you see some domestic cattle sharing space with some wild antelope. Observation: The cattle and the antelope are standing quietly together Inference: The cattle and antelope do not attack each other. Inference: None of the animals in this region attack each other.

O BSERVATION OR I NFERENCE ? There’s an empty aquarium tank in the classroom. The tank used to contain live fish. The tank is 50 cm long, 30 cm wide and 18 cm deep. The tank has a leak in it. The teacher likes fish.

What observations and inferences can you make from this data about family shopping habits? FamilyVegetablesMeatDetergent Smith $ 30 $ 40 $ 8 Barney $ 20 $ 26 $ 6 Miller $ 18 $ 24 $ 6 Edwards $ 14 $ 18 $ 4 Brady $ 40 $ 0 $ 16 Douglass $ 104 $ 146 $ 0

P REDICTING /M AKING A HYPOTHESIS Predicting is making an inference about a future event based on current evidence or past experience; It is not a guess. One way to make a prediction is to look for a pattern. Because a prediction is an inference, it may not always be correct. Predictions can be tested by observation and/or experimentation.

P REDICTION … CONTINUED Why is making a prediction in science different than just guessing?